1. Field of the Invention
The present invention relates to devices or assemblies used in tissue repair. More particularly, the assembly enables the attachment together or repair of portions of biological tissue (i.e., tendons or ligaments) onto a bone surface.
2. Description of the Background Art
Soft tissues, such as tendons and ligaments, generally are attached to bone by small collagenous fibers. These connections are strong but permit the tendons and ligaments to be flexible. When a tissue is torn away from the bone and requires repair, a surgeon is often required to repair the detached soft tissue with sutures which are passed through bone tunnels and tied. A number of devices have been developed for securing a ligament or tendon to a bone mass. These devices can be used in place of bone tunnelling techniques. These attachment devices are usually inserted through extensive surgical incisions and, in some circumstances, by arthroscopic surgical techniques. The use of bone tunnels for repair can be difficult and generally require large open incisions. Recently, through the advent of endoscopic surgery, where the surgeon looks into a joint cavity with a telescope, there has been a trend to repair soft tissues back to bone through small incisions called portals. The unique knotless suture anchor assemblies described herein facilitate this difficult and precise procedure.
A variety of devices are available for attaching objects to bone, such as screws, staples, cement, suture anchors, and sutures alone. These devices have been used to attach soft tissue, such as ligaments, tendons, muscles, as well as objects such as prostheses, to bone. A suture anchor is a device which utilizes small anchors with suture materials attached thereto. A device, such as a screw, is inserted into the bone mass and anchored in place. After insertion of the anchor, the attached suture is passed through the tissue to be repaired. The tying of a knot in the suture is then required to secure the tissue to the bone. The process of passing the anchored suture through the soft tissue and tying a knot is time consuming and difficult to undertake in the tight space encountered during endoscopic surgery and sometimes even in conventional open surgery.
One example of a suture anchor assembly is disclosed in U.S. Pat. No. 5,370,662, wherein an anchor assembly includes a pre-threaded suture positioned at its posterior. First the anchor is inserted into the bone mass. The attached suture is then passed through the tissue for reattachment. The surgeon is required to tie a knot with the suture to complete the surgical process. Some suture anchors can be passed through the soft tissue first and then into the bone. Most suture anchors need to be inserted into the bone first. Only after this has been accomplished can the sutures be passed through the soft tissue. Alternatives to this procedure include non-suture soft tissue anchor systems. A few of these systems, such as those disclosed in U.S. Pat. Nos. 5,013,316 and 4,532,926, can be used arthroscopically but fixation with these devices may not be as secure as that achieved with sutures. Only a few points of fixation are possible with the non-suture type anchor since the device is relatively large. Therefore suture devices are more favorable. This type of non-suture staple device is disadvantageous in that it has been known to crack the bone during deployment, or accidentally transect the object being attached to the bone. In addition, the device itself has been known to crack or break during or after deployment.
U.S. Pat. Nos. 5,037,422; 5,224,946; and 5,236,445 all disclose bone anchor configurations for attaching sutures within openings formed in bones during joint reconstructive surgery and endoscopic surgical procedures. With all these intricate procedures, the suture itself must be inserted through a tissue mass and tied with a surgical knot to repair the soft tissue to bone.
A primary object of the present invention is to provide a suture anchor assembly which is easy to use and install.
Another object of the present invention is to provide a suture anchor assembly which allows for secure attachment of soft tissue to bone without the use or requirement of tying a knot.
Still another object of the present invention is to provide a suture anchor assembly which is compact and allows a surgeon to easily guide the tissue into a bone anchoring sleeve to enhance the security of the repair.
Still another object of the present invention is to provide an anchor assembly which allows for passage through soft tissue in a singular fashion without the need for additional instrumentation for passing the suture separately through the soft tissue to be repaired.
In accordance with the above objects, the present invention is a knotless suture anchor assembly for attachment or reattachment of biological soft tissue to bone. The unique knotless suture anchor assembly can be a one-piece device or include a hollow anchoring sleeve which is installed into a bone mass. The knotless suture anchor assembly or the anchoring sleeve can have a closed pointed drill end or be totally cylindrical in shape. The hollow one-piece assembly or anchoring sleeve can be ribbed or threaded on its exterior for secure attachment to the bone or embody varying types of conventional anchor configurations to facilitate a strong bond with the bone mass. A number of prior patents disclose configurations for the exterior of a bone anchor which are within the contemplation of the invention for use as the anchoring means for the exterior of the hollow anchoring sleeve.
Incorporated by reference are U.S. Pat. Nos. 4,007,743; 4,632,101; 4,721,103; 4,870,957; 4,898,156; 4,946,468; 5,084,050; 5,102,421; 5,141,520; 5,192,303; and 5,207,679, which all illustrate varying exterior structures which may embody the anchoring sleeve portion of the invention. These patents disclose various means and mechanisms for anchoring a device to a bone mass thus preventing pull-out of the sleeve after insertion into bone.
Further, the hollow anchoring sleeve can contain a collar on the rear portion or rear side of the hollow anchoring sleeve to control the depth of sleeve insertion into the bone and prevent excessive insertion depth.
A key component of the knotless one-piece or two-piece suture anchor assembly is the spike or plug member which has on its first end a configuration which allows for easy puncturing of a soft tissue and on its second or other end a means for attachment of a suture material. The first end can be pointed or frustoconical in shape. The spike or plug can be ribbed, beaded, threaded or expandable on its exterior surface for secure mating with the interior wall section of the hollow anchoring sleeve or the bone directly. The suture material which is attached to the rear end of the spike or plug member has attached thereto a stop means for grabbing the tissue to be reattached to the bone mass. The stop means is produced or made from various materials and is attached to the spike or plug by a selected length of suture.
The spike or plug member, suture and stop means can be all produced of the same material (i.e., molded). This would obviate need for the second end of the spike or plug member to have means for attachment of the suture thereto.
In the two-piece configuration, the spike or plug member is inserted during an open or endoscopic procedure, or the like, through the soft tissue and its piercing or pointed end is then inserted into the anchoring sleeve to facilitate a secure mating. Once the spike or plug member is threaded through the tissue and is inserted into the hollow anchoring sleeve, it is then securely attached through pressure by the surgeon into the sleeve. This attachment of the spike member to the hollow anchoring sleeve can be accomplished in one step or in a number of depth control steps (i.e., ratchets) to fine tune the tightness of the repair. This ratchet effect can be accomplished by a series of beads, ribs, thickening or the like on the exterior of the spike component. These would mate with the interior of the anchor sleeve. This allows for the tissue to be tightly attached to the bone mass. The unique device obviates the need for the surgeon to tie a knot with the suture material for reattachment of tissue to bone. Endoscopic procedures and some open surgical procedures are extremely difficult and must be completed in a very tight space. Obviation of the need of tying a knot is extremely beneficial and innovative.
In addition, it is within the contemplation of this invention to produce a one-piece knotless suture anchor assembly that includes a spike or plug member which can act as the bone anchor and spike without the necessity of a hollow anchoring sleeve. The spike or plug member, suture and stop means are identical to that described above with the added feature of the spike or plug member having a bone anchoring means on its exterior surface.
The one-piece embodiment can be installed as described above. That is the spike or plug can be inserted through the soft tissue and then into the bone with the stop means grabbing the tissue and attaching or reattaching same to the bone mass. In the alternative, the stop means of the one-piece device can be inserted from the underside of the tissue mass through the mass, thereby obviating the need for the spike or plug with anchoring means from passing through the tissue. The spike or plug with anchor is then pressed into the bone mass pulling the tissue into attachment or reattachment to the bone mass.
As previously described, the suture and stop means can vary in shape and be produced of the same or different materials.
Numerous other features of various embodiments of the knotless suture anchor assembly will be apparent from the following detailed description and the accompanying drawings.